SNVSB75D December   2018  – January 2021 LM5155 , LM51551

PRODUCTION DATA  

  1. Features
  2. Applications
  3. Description
  4. Revision History
  5. Description (continued)
  6. Device Comparison Table
  7. Pin Configuration and Functions
  8. Specifications
    1. 8.1 Absolute Maximum Ratings
    2. 8.2 ESD Ratings
    3. 8.3 Recommended Operating Conditions
    4. 8.4 Thermal Information
    5. 8.5 Electrical Characteristics
    6. 8.6 Typical Characteristics
  9. Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1  Line Undervoltage Lockout (UVLO/SYNC Pin)
      2. 9.3.2  High Voltage VCC Regulator (BIAS, VCC Pin)
      3. 9.3.3  Soft Start (SS Pin)
      4. 9.3.4  Switching Frequency (RT Pin)
      5. 9.3.5  Clock Synchronization (UVLO/SYNC Pin)
      6. 9.3.6  Current Sense and Slope Compensation (CS Pin)
      7. 9.3.7  Current Limit and Minimum On-time (CS Pin)
      8. 9.3.8  Feedback and Error Amplifier (FB, COMP Pin)
      9. 9.3.9  Power-Good Indicator (PGOOD Pin)
      10. 9.3.10 Hiccup Mode Overload Protection (LM51551 Only)
      11. 9.3.11 Maximum Duty Cycle Limit and Minimum Input Supply Voltage
      12. 9.3.12 MOSFET Driver (GATE Pin)
      13. 9.3.13 Overvoltage Protection (OVP)
      14. 9.3.14 Thermal Shutdown (TSD)
    4. 9.4 Device Functional Modes
      1. 9.4.1 Shutdown Mode
      2. 9.4.2 Standby Mode
      3. 9.4.3 Run Mode
  10. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
        1. 10.2.2.1 Custom Design With WEBENCH® Tools
        2. 10.2.2.2 Recommended Components
        3. 10.2.2.3 Inductor Selection (LM)
        4. 10.2.2.4 Output Capacitor (COUT)
        5. 10.2.2.5 Input Capacitor
        6. 10.2.2.6 MOSFET Selection
        7. 10.2.2.7 Diode Selection
        8. 10.2.2.8 Efficiency Estimation
      3. 10.2.3 Application Curve
    3. 10.3 System Examples
  11. 11Power Supply Recommendations
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Examples
  13. 13Device and Documentation Support
    1. 13.1 Device Support
      1. 13.1.1 Third-Party Products Disclaimer
      2. 13.1.2 Development Support
        1. 13.1.2.1 Custom Design With WEBENCH® Tools
    2. 13.2 Documentation Support
      1. 13.2.1 Related Documentation
    3. 13.3 Receiving Notification of Documentation Updates
    4. 13.4 Support Resources
    5. 13.5 Trademarks
    6. 13.6 Electrostatic Discharge Caution
    7. 13.7 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

Electrical Characteristics

Typical values correspond to T= 25°C. Minimum and maximum limits apply over T= -40°C to 125°C. Unless otherwise stated, VBIAS = 12 V, R= 9.09 kΩ
PARAMETERTEST CONDITIONSMINTYPMAXUNIT
SUPPLY CURRENT
ISHUTDOWN(BIAS)BIAS shutdown currentVBIAS = 12 V, VUVLO = 0 V2.65uA
IOPERATING(BIAS)BIAS operating currentVBIAS = 12 V, VUVLO = 2 V, VFB = VREF, RT = 220 kΩ480540uA
VCC REGULATOR
VVCC-REGVCC regulationVBIAS = 8 V, No load6.56.857V
VCC regulationVBIAS = 8 V, IVCC = 35 mA6.5V
VVCC-UVLO(RISING)VCC UVLO thresholdVCC rising2.752.852.95V
VCC UVLO hysteresisVCC falling0.063V
IVCC-CLVCC sourcing current limitVBIAS = 10 V, VVCC = 0 V35105mA
ENABLE
VEN(RISING)Enable thresholdEN rising0.40.520.7V
VEN(FALLING)Enable thresholdEN falling0.330.490.63V
VEN(HYS)Enable hysteresisEN falling0.03V
UVLO/SYNC
VUVLO(RISING)UVLO / SYNC thresholdUVLO rising1.4251.51.575V
VUVLO(FALLING)UVLO / SYNC thresholdUVLO falling1.3701.451.520V
VUVLO(HYS)UVLO / SYNC threshold hysteresisUVLO falling0.05V
IUVLOUVLO hysteresis currentVUVLO = 1.6 V456uA
SS
ISSSoft-start current91011uA
SS pull-down switch RDSON55Ω
PULSE WIDTH MODULATION
fsw1Switching frequencyRT = 220 kΩ85100115kHz
fsw2Switching frequencyRT = 9.09 kΩ198022002420kHz
tON(MIN)Minimum on-timeRT = 9.09 kΩ50ns
DMAX1Maximum duty cycle limitRT = 9.09 kΩ80%85%90%
DMAX2Maximum duty cycle limitRT = 220 kΩ90%93%96%
CURRENT SENSE
ISLOPEPeak slope compensation currentRT = 220 kΩ22.53037.5uA
VCLTHCurrent Limit threshold (CS-PGND)93100107mV
HICCUP MODE PROTECTION (LM51551)
Hiccup enable cycles64Cycles
Hiccup timer reset cycles8Cycles
ERROR AMPLIFIER
VREFFB referenceLM5155, LM515510.9911.01V
GmTransconductance2mA/V
COMP sourcing currentVCOMP = 1.2 V180uA
COMP clamp voltageCOMP rising (VUVLO = 2.0V)2.52.8V
COMP clamp voltageCOMP falling11.1V
OVP
VOVTHOver-voltage thresholdFB rising (referece to VREF)107%110%113%
Over-voltage thresholdFB falling (referece to VREF)105%
PGOOD
PGOOD pull-down switch RDSON1 mA sinking90Ω
VUVTHUndervoltage thresholdFB falling (referece to VREF)87%90%93%
Undervoltage thresholdFB rising (referece to VREF)95%
MOSFET DRIVER
High-state voltage drop100 mA sinking0.25V
Low-state voltage drop100 mA sourcing0.15V
THERMAL SHUTDOWN
TTSDThermal shutdown thresholdTemperature rising175°C
Thermal shutdown hysteresis15°C